Machine for pulling pins



Nov. 3, 1959 F. CREASON MACHINE FOR PULLING PINS 2 Sheets-Sheet 1 FiledSept. '7, 1954 INVENTOR. fian/v' Creasan.

Nov. 3, 1959 I F. CREASON 2,911,190

MACHINE FOR PULL-INC PINS Filed Sept. '7, 1954 2 Sheets-Sheet 2 U IIIIII 5 i 65 5 gi --17 12 M 22 I N V EN TOR. 500k Creas 0n.

A TTORMEYS.

United States Patent MACHINE FOR PULLlNG PINS Frank Creason, Liberty,MO.

Application September 7, 1954, Serial No. 454,517 4 Claims. (Cl. 254-18)This invention relates toa machine for pulling pins of the type used inanchoring road and similar forms.

For example, in the building of roadways, landing strips and the like,metal sections are placed upon the ground to provide forms between whichconcrete and similar paving materials are poured. These forms areanchored in position by pins or rods that are driven through pin socketsof the form sections and into the ground. After the paving material hasbeen poured and set to the desired degree, the pins are withdrawn andforms removed for re-use as the construction advances.1,

It is therefore the principal object of the present invention to providea portable machine adapted to move along the surfaceof the roadway andwhich is equipped with power actuated means for gripping, pulling andreleasing the pins.

Other objects of the invention'are to provide a ma chine of thischaracter with a pressure operated foot member for applying a holdingpressure on the form and to hold themachine stable while a pin is beingremoved; to provide apressure foot that may be lowered to any positionnecessary for applying a solid footing thereof; to provide asubstantially balanced, easily maneuverable machine wherein the pullingand pressure foot mechanisms are suspended in space over the side of theform and in position to effect their respective functions withouttilting of the machine.

In accomplishing these and other objects of the invention as hereinafterpointed out, I have provided improved structure the preferred form ofwhich is illustrated in the accompanying drawings wherein:

Fig. 1 is a perspective view of a pin pulling machine constructed inaccordance with the present invention and illustrating use thereof forpulling the pins used in anchoring road and similar forms.

Fig. 2 is a front elevational view of the machine with the form androadway shown in section and portions of the machine broken away tobetter illustrate the invention.

Fig. 3 is a side elevational View of the pin gripping head showing thejaws in open position and ready to engage the end of a pin.

Fig. 4 is a similar view showing the jaws in gripping engagement withthe pin.

Fig. 5 is a similar view showing the jaws in released position to dropthe pin after withdrawal thereof.

Fig. 6 is a cross section on the line 66 of Fig. 4.

Fig. 7 is a horizontal-section on the line 7-7 of Fig. 4.

Fig. 8 is a fragmentary view showing the hydraulic I cylinder foractuating the pressure foot, a portion of the cylinder being shown insection to better illustrate the piston contained therein.

Fig. 9 is a diagrammatic view of the hydraulic system employed in themachine.

Referring more in detail to the drawings:

1 designates one sideof a portion of a concrete slab which may be aroadway, landing strip of an airfield, or the like which requires sideforms 2 in the construction plate 35. I Fixed to the floor sheet of theplatform alongside of "ice thereof. The side forms 2 are composed of aplurality of end-to-end sections each of which includes a base flange 3adapted for support upon the ground or grade which carries the concreteslab, a vertical Web 4 extending along the inner-side edge of the baseflange 3 and an outwardly and downwardly turned flange 5 which forms arail along the upper edge of the web and which is utilized in supportingthe equipment for pouring and spreading the concrete.

Located at intervals along the length of each form section are braces 6having pin sockets 7 through which pins 8 are driven into the ground toanchor the form section infixed position. After the concrete is set, thepins 8.

Fixed to the underside of the platform portion 11, sub-.

stantially in the transverse center of gravity of the machine, arebrackets 14 and 15 carrying a transverse axle 16, the ends of the axlebeing suitably secured to the brackets. Rotatably mounted on the axle atthe innersides of the brackets 14 and 15 are wheels 17 and 18 having asuitable diameter to support the base portion 12 of the framesubstantially in contact with the surface of the slab Whenthe platformportion 11 is substantially horizontal. The side and rear marginal edgesof the platform portion are preferably provided with depending flanges19 to stiffen the floor sheet 20 of the platform. The off-set portions13 of the frame is formed by a transverse plate 21 that depends from theforward edge of'the floor sheet 20 and carries on its lower edge ahorizontal plate 22 having a flat lower face 23 which terminates alongthe front edge thereof in an up-turned flange 24. The plate 22 is bracedat one side of the frame between an end of the flange 24 and the plate21 by a gusset plate 25.

The frame thus described may be formed of a single sheet ofmaterial bentto shape or it may be formed of separate sheets suitably welded togetherto provide a solid structure.

Extending upwardly and rearwardly'from the sides of the platform portionof the frame are handle bars 26 and 27 having hand grips 28 and 29. Thehandle bar 27 is preferably fixed to the floor sheet 20 at that side ofthe frame but the handle bar 26 may be attached to a bracket 30 that isfixed to the platform for a purpose later described. The handle bars 26and 27 may be connected at the ends thereof by a cross bar 31 and theymay be suitably braced from the rear portion of the platform by bars 32.

The bracket 30 includes front and rear vertical legs 33 and 34 connectedat their upper ends by a downwardly and-forwardly sloping plate 35. Theleg 34 is braced at the sides by gussets 36 to provide a suflicientlystrong support for mounting a valve unit 37 upon the sloping I thebracket 30 are laterally spaced plates 38 and 39 carrying a tank 40 forcontaining a hydraulic fluid used in operating the mechanism of themachine as later described. Mounted on the platform between the tank 40and the handle bar 27 and slightly forward of the tank is an engine 41for driving a pump 42. The pump 42 is also mounted on the platform tothe rear of the engine and is operably, connected with the enginethrough a pulley and belt drive 43.

The valve assembly 37, engine 41 and pump 42 are mounted as described toassist in balancing hydraulically actuated jack cylinders 44 and 45 thatare supported from the side of the frame as now to be described.

Extending upwardly from the plate 22 and fixed to the plate 21 andflange 24 are standards 46 and 4-7. The upper ends of the standardsterminate in lateral arms 43 and 49 projecting from the side of themachine as best shown in Fig. 1. The outer ends of the arms 48 and 49are connected by a cross bar 50 that supports the cylinder 44. Slidablymounted in the cylinder 44 is a piston 51 dividing the cylinder intoupper and lower chambers 52. and 53. The upper end of the cylinder isclosed by a head 54, while the bottom of the chamber 53 is closed by asimilar head 55. Connected with the piston 51 is a piston rod 56 thatpasses through a suitable seal in the lower head through an opening 57in the cross bar 50 and carries on the lower end thereof a head 58. Thehead 58 has laterally extending ears 59 and 60. Pivotally connected withthe ears 59 and 60 by pivots 61 and 62 are toggle arms 63 and. 64. Thetoggle arms 63 and 64 pivotally connect by means of pins 65 and 5-6 withthe arms 67 and 68 of gripping jaws 69 and 70. The jaws 69 and 70 arepivotally mounted on cross bars 71 and 72 of a rectangular frame 73. Thejaws 69 and 70 have gripping faces 74 and 75 suitably shaped to en: gageunder the head 76 of the pin 8. The toggle arms 63 and 64 and the jawarms 67 and 68 have interengaging stop lugs 77 and 78 which interengageto hold the jaws when held in suspended position.

In order to prevent rotation of the guide head, the upper portion of thecylinder 44 mounts a clamp 79 having a laterally extending bearing lug80 which slidably retains the upper end of a guide rod 81, the lower endof which is fixed to a pin 82 extending laterally from a side of thehead 58 as best shown in Fig. 2.

The cylinder 45 has its upper end attached to a bracket 83 that iscarried from the arm 48 of the standard 46. The lower end of thecylinder is attached to the adjacent side flange 18 of the platformsection of the frame, as shown in Fig. 1, to support the cylinder invertical position. Slidably mounted in the cylinder 45 is a piston 84dividing the cylinder into an upper chamber 85 and a lower chamber 86.Slidably sealed in the lower end of the cylinder is a piston rod 87 thatconnects with the piston 84 at its upper end and its lower end carries afoot 88 that is adapted to be lowered into engagement with the flange 3of the form as later described.

The cylinders thus described are supplied with a hydraulic fluid fromthe tank 40 under pressure of the pump 42. The tank 40 is connected withthe inlet of the pump through a duct 89 and the discharge connection ofthe pump connects through a duct 90 with inlets 91 and 92 of controlvalve 93 and 94 forming the valve unit 37 (see Fig. 9), the connectionbeing made by flexible ducts 95 and 96.

The valves 93 and 94 are the four-Way type and have outlets 97, 98 and99 for the valve 93 and outlets 100, 101 and 102 for the valve 94. Theoutlets98 and 101 connect with tank 46 through a return duct 103. Theoutlets 97 and 99 of the valve 93 connect through flexible ducts 104 and1.05 with the upper and lower ends of the cylinder'44. The outlets and102 of the valve 94 are similarly connected through flexible ducts 106and 107 with the upper and lower ends of the cylinder 45 so as to supplyfluid under pressure alternately to the upper and lower ends of therespective cylinders as later to be described.

The valves 93 and 94 are actuated through rods108 and 109 that connectwith operating levers 110 and 111 carried on the cross bar 31 previouslydescribed.

Depending from the arms 43 and 49 are trips 112 and 113 adapted toengage the outer end portions of the jaw arms 67 and 68 to rock the jawsand effect release of the pins on the up-stroke of the piston 51.

In using the machine constructed andassembled as described, and assumingthat the engine 41 is in operation to drive the pump 42, a pressure isbuilt up in the ducts 90, 95 and 96 to furnish a supply of pressuremedium to the inlets 91 and 92 of the valves 93 and 94 when the valvesare open as later described. The machine having been placed upon theconcrete slab is moved into position where the jaws of the gripping headare over a pin 8 to be pulled. The machine is readily moved intoposition by bearing down on the handle bars 26 and 27 to raise the face23 of the base plate 22 of the frame from contact with the surface ofthe slab and pushing the machine "somewhat in the manner of a handtruck. 7 When the gripping head is in position relative to the pin. thevalve control levers 110 and 1 11 are actuated to shift the valves 93and 94 so as to supply pressure fluid to the upper ends of the cylinders44 and 45. The pressure fluid flows from the duct 95 through the valve93 to the duct 104 and to the upper end of the cylinder .44 where itdischarges into the upper chamber 52 to move the piston downwardly.During this movement of the piston 51 the, pressure fluid under thepiston is forced out of the cylinder through the duct 105,

; valve connections 99 and 98, and returned to the tank into pressingcontact with the flange 3. The fluid below the piston 84 is displacedfrom the chamber 86 and discharged through the duct 106, valveconnection 1&0 and 101 and returned to the tank 40 through the duct 103.When the foot 88 is in contact with the flange the valve 94 is closed totrap the fluid in both chambers 85 and 86 of the cylinder therebyretaining the foot 88 in fixed relation relative to the surface of theslab 1 to cooperate with the base portion 12 of the frame of the machinein providing reaction forces against the face of the con- Crete-andflange 3 of the form when the pin is being pulled from the pin socket.To pull the pin, the valve operating lever 111 is shifted so as toconnect the pressure supply duct 95 with the duct and to connect theduct 104 with the return duct 103. The pressure fluid is then admittedto the chamber 53 to act under the piston to lift the gripping head. Asthe gripping head is carried upwardly, the jaws 69 and 70 engage underthe head 76 of the pin as shown in Fig. 4. Continued upward movement ofthe gripping head pulls the pin 3 from the ground through pin socket.When the pulling force is applied to the pin the foot 88 eliminates anytendency for the machine to tilt sidewise under the pulling force. Whenthe gripping head approaches the upper end of the stroke, the free endsof the jaw arms 67 and 63 come into contact with the trips 112 and 113to stop further upward movement of the jaws. However, due to theconnection of the links 63 and 64 with the head 58, the jaws are rockedoutwardly and away from contact with the pin and the pin 8 drops fromthe jaws and through the jaw supporting frame 73 as shown in Fig. 5.Upon release of the pin 8, the lever 111. is shifted to cut-elf the flowof pressure fluid to the lower end of the cylinder.

The control lever 111 is then actuated to shut-01f flow of pressurefluid to the cylinder 44, thereby suspending operation of the grippinghead. The valve control lever is then operated to actuate the valve 94so that the pressure fluid acts through the duct 106 and against theunderside of the piston 84 while the pressure fluid in the upper end ofthe cylinder 45 is discharged through the duct 107 and returned to thetank 40. The pressure the handle bars to tip the frame of the machineslightly about the axis of the axle 16 to raise the base portion 12 ofthe frame and permit moving of the machine along the edge of the slabuntil the gripping jaws are in registry with another of the pins,whereupon the base portion of the frame is again allowed to come intocontact with the surface of the slab and the operations, as abovedescribed are repeated. The procedure continues along the length of theform, after which the machine is moved to the opposite side of the slabto pull the pins holding the form on that side.

Attention isrdireeted to the fact that the length of the piston rods andcylinders are such as to allow the necessary movement to engage and pullthe longest pin and to seat the foot 88 in supporting contact with theflange 3 of the height of form. It sometimes happens that concrete maybe spilled on the form 3 so that the foot 88 comes into contact with thehardened concrete, however, the pressure of the foot is applied throughthe concrete to the form so as to hold the form in position and preventany tendency of the machine to tilt under the force required to pull thepin.

From the foregoing it is obvious that I have provided av pin pullingmachine that is of simple and inexpensive construction and which isreadily maneuverable along the side of slab for pulling the pins thatretain the forms.

What I claim and desire to secure by Letters Patent 1. A machine forpulling pins that retain forms at sides of a concrete slab in road andsimilar'construction, said machine including a mobile frame adapted tobe moved upon the slab along the side of the form, a

fluid pressure actuated mechanism on the frame for engaging and pullingthe pins, a separate fluid pressure actuated mechanism on the frame forengaging and applying a downward pressure on the form during actuationof the pin pulling means, and means on the frame for manuallycontrolling the fluid pressure to and from said mechanisms.

2. A machine. for pulling pins that retain forms at sides of a concreteslab in road and similar construction, said machine including a mobileframe having a base portion adapted to bear upon said slab, a jacksupport extending upwardly from said frame and having a lateral actuatedjack carried by the projecting portion of said jack support, a grippinghead suspended from the power actuated jack for engaging and pulling apin upon operation of the jack, means carried by said projecting portionfor engaging a part of the form to retain said forms and to preventlateral tilting of the machine under pull of said jack, fluid pressuremeans for actuating said jack including said form retaining means, ahandle bar carried by the platform section of the frame to facilitatemovement of the frame, and control means carried by the handle bar forcontrolling the fluid pressure means to selectively operate said jackand the form retaining means.

4. A machine for pulling pins that retain forms at sides of a concreteslab in road and similar construction, said machine including a'framehaving a base portion adapted to bear upon said slab and off-setdownwardly from the platform portion, brackets depending from saidplatform portion of the frame, an axle carried, by the brackets, wheelson the axle for providing a mobile support for the frame and to form apivot on which the frame is tilted to move said base portion into andout of said bearing contact with the slab, a jack support extendingupwardly from said base portion of the frame and having a lateralportion projecting from aside of the frame, a power actuated jackcarried by said projecting portion, a gripping head suspended from thepower actuated jack for engaging and pulling the pin upon operation ofthe jack, means carried by said projecting portion for engaging a partof the form to prevent lateral tilting of the machine under pull of saidjack, fluid pressure means for actuating said jack including said formretaining means, handle bars carried by the platform section of theframe to facilitate said movements of the frame on said wheels, andcontrol means carried by the handle bars for controlling the fluidpressure means to selectively operate said jack and the form retainingmeans.

References Cited in the file of this patent UNITED STATES PATENTS1,880,338 Benson Oct. 4, 1932 1,893,719 Talboys Jan. 10, 1933 2,157,214Okuda May 9', 1939 2,318,108 Schramm May 4, 1943 2,361,197 Hallinan Oct.24,- 1944 2,636,715 Griflin Apr. 28, 1953 2,639,888 Kilness May 26, 19532,691,505 Hursh Oct. 12, 1954 2,733,950 Janzer et al. Feb. 7, 1956

